Hi
This may be a totally twp question but I have just finished level 2 lesson 18 and the phrase
“What would you say” and “what would you do” was covered.
The welsh was “Be’ fyddet ti’n dweud /gneud” was given.
However I thought the word for would was basen and I would have said “Be’ baset ti’n dweud”
What you’ve discovered here is that there are two ways of saying ‘would’ in Welsh. Both are correct and it’s just personal/regional preference as to which you use. An extremely light rule of thumb is the byddwn set in the South and the baswn set in the North, but this is by no means set in stone, as you’ll hear both wherever you are depending on which the speaker prefers to use.
Whichever one you use, the b will mutate to f when it’s a question, so the only tweak to what you would have said is “Be’ faset ti’n dweud”.